共查询到20条相似文献,搜索用时 343 毫秒
1.
Re-interpretation of Wexfordia hookense from the Upper Devonian of Ireland as an arborescent lycophyte 总被引:4,自引:0,他引:4
SHARON D. KLAVINS 《Botanical journal of the Linnean Society. Linnean Society of London》2004,144(3):275-287
New collections of pyritized axes of the lycophyte Wexfordia hookense have been made from the Upper Devonian (uppermost Famennian) type locality at Sandeel Bay, County Wexford, in south-eastern Ireland. The specimens reveal additional histological features that permit reinterpretation of the morphology of this taxon and reevaluation of its taxonomic affinities. Wexfordia is shown to possess both secondary xylem, with narrow, uni- to biseriate rays, and periderm. The range of variation in relative amounts of primary and secondary xylem can be correlated with position in the mature plant. This evidence indicates that Wexfordia was a small tree rather than an herbaceous form. Fine structure of tracheids and additional anatomical features strongly support affinities with Carboniferous arborescent Isoetales, rather than Devonian Protolepidodendrales, and further support the hypothesis that radiation in this lineage was well underway prior to the Carboniferous. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 275–287. 相似文献
2.
Y. WANG H. H. XU 《Botanical journal of the Linnean Society. Linnean Society of London》2005,149(3):299-311
Sublepidodendron wusihense (Sze) Sze and Lepidostrobus grabaui Sze were based on compressions from the upper part of the Wutung Formation (Famennian) of Jiangsu, South China. After studying the morphology and anatomy of abundant well-preserved specimens from two localities, Sublepidodendron wusihense and Lepidostrobus grabaui are reconsidered and viewed as Sublepidodendron grabaui (Sze) comb. nov. This plant is an arborescent, heterosporous lycopsid known from trunk, branches and cones. Leaf bases are spirally arranged, fusiform in outline, with a vascular bundle scar and keel. One specimen is known with a cone attached at the tip of a distal branch. The trunk has an intrastelar parenchyma concentration (pith), exarch primary xylem and secondary xylem. The branch anatomy varies from exarch primary xylem with a small, centrally located pith, to a solid exarch primary xylem strand. Based on the morphology and anatomy of both vegetative and reproductive organs, Sublepidodendron grabaui is placed into Sublepidodendraceae ( sensu Kräusel & Weyland, 1949), and Isoëtales ( sensu DiMichele & Bateman, 1996). © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 299–311. 相似文献
3.
The basipterygoid articulation, an articular connection between the base of the braincase and the palatoquadrate, is widespread among gnathostome vertebrates. However, among living teleosts it is present only in the osteoglossomorphs Arapaima , Heterotis , Scleropages , Osteoglossum and Pantodon . Study of the development of the hyopalatine arch and the basipterygoid articulation in Pantodon buchholzi based on an ontogenetic series of cleared and double stained specimens yielded the following results: the symplectic process of the hyosymplectic cartilage never develops and the symplectic is absent; the pars hyomandibularis fuses with the palatoquadrate; the dermopalatine and ectopterygoid originate as separate bones, but fuse subsequently; the basal process is first visible on the pars metapterygoidea of the palatoquadrate at 7.0 mm standard length (SL); at 11.5 mm SL the basipterygoid process appears on the parasphenoid and contacts the basal process, establishing the basipterygoid articulation; the endopterygoid is initially not involved in the articulation, but during subsequent development enlarges and eventually forms an articular groove for the reception of the basipterygoid process of the parasphenoid; the distal tip of the basal process of the metapterygoid, however, still forms the caudolateral part of the articular groove in the adult. We discuss previous hypotheses about the homology of the basipterygoid articulation of osteoglossoids in light of these findings. Based on the numerous shared similarities and its occurrence in all major actinopterygian lineages, we argue that the basipterygoid articulation in osteoglossoids is homologous to that in non teleostean actinopterygians and represents a plesiomorphic character state at the level of Osteoglossomorpha. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 1−13. 相似文献
4.
VERONICA DE MICCO GIOVANNA ARONNE 《Botanical journal of the Linnean Society. Linnean Society of London》2007,155(3):361-371
Mediterranean shrub species are described as having phenology, habitus , reproductive biology and anatomical alterations in certain tissues, allowing their survival during the dry season and protecting them from herbivory. Anatomical and chemical analyses were conducted in 1-year-old branches of Cistus ladanifer L. in order to investigate the role played by shoot structure in the adaptive strategies of this species in the Mediterranean environment. Results showed that both xylem and pith underwent lignification. Pith parenchyma cells had thickened walls, higher lignin content than xylem and different monomer composition. Xylem presented features aiding safe water transport. A large accumulation of phenolic substances was found in xylem, pith and cortical parenchyma. Observations reported in this paper suggest the occurrence of adaptive strategies in 1-year-old branches of C. ladanifer whose structural features: (1) allow mechanical reinforcement of tissues to withstand drought without suffering permanent damage; (2) favour safety rather than efficiency in water transport; (3) defend the plants from animal predation and pathogens by accumulating phenolics in various tissues, and (4) protect inner tissues against UV-B radiation through deposition of phenolic compounds in cortical layers. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155 , 361–371. 相似文献
5.
Rotafolia songziensis gen. et comb. nov., a sphenopsid from the Late Devonian of Hubei, China 总被引:3,自引:0,他引:3
DE-MING WANG SHOU-GANG HAO QI WANG 《Botanical journal of the Linnean Society. Linnean Society of London》2005,148(1):21-37
A sphenopsid from the Upper Devonian (Famennian) Xiejingsi Formation, south-western Hubei Province, China, previously named as various species in Sphenophyllum , Hamatophyton , Bowmanites and Sphenophyllostachys , is now reinvestigated and assigned to a new taxon, Rotafolia songziensis gen. et comb. nov. Its ribbed axes are anisotomous and possess slightly expanded nodes. Lateral axes are inserted at nodes on main axes. Whorls of much divided vegetative leaves are attached at nearly right angles to nodes of basal axes, and at acute angles to nodes of terminal axes. There are six leaves per whorl. The terminal strobilus includes a central axis and verticils of fertile units. Each fertile unit consists of a bract and numerous sporangia. The margin of the elongate-cuneate bract bears a distal and many lateral elongate segments. Clusters of elongate sporangia are abaxially attached to the base of the bract at the same level. The axis has an actinostele, composed of a three-ribbed, exarch primary xylem and radial secondary xylem. Although Rotafolia songziensis closely resembles Hamatophyton verticillatum in axis character, leaf morphology and primary xylem type, they are quite different in strobilar structure. Taxonomically, Rotafolia is placed in the order Sphenophyllales by three well-defined characters: 1) whorled appendages; 2) ribbed protosteles; 3) exarch primary xylem maturation. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 21–37. 相似文献
6.
7.
8.
XIAN-CHUN ZHANG QIAO-PING XIANG HANS P. NOOTEBOOM 《Botanical journal of the Linnean Society. Linnean Society of London》2005,148(3):323-327
Selaginella hainanensis X.C.Zhang & Noot. sp. nov. , a new species from Hainan Island, South China, is described and illustrated. Diagnostic notes and a key to the species distributed in Hainan are also provided. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 323–327. 相似文献
9.
NASR M. S. HASSAN ULRICH MEVE SIGRID LIEDE-SCHUMANN fls 《Botanical journal of the Linnean Society. Linnean Society of London》2005,148(2):189-206
Macro- and micromorphological characters of the seeds of 32 species belonging to Aizoaceae (26 species), Gisekiaceae (one species) and Molluginaceae (five species) were analysed for their taxonomic value. Seed morphology is found to be of considerable taxonomic value within the taxa investigated, although additional criteria are usually necessary for distinguishing the species. However, a subgroup of Trianthema , consisting of T. cussackiana , T. megasperma , T. pilosa , T. rhynchocalyptra and T. oxycalyptra var. oxycalyptra (Aizoaceae) shares the synapomorphy of seeds with scattered idioblast cells (papillae). There is little infrageneric variation within Sesuvium and Zaleya in contrast to Trianthema , whose seeds are considerably polymorphic. The fairly different seed structures found in Aizoaceae s.s . and Molluginaceae support their treatment as two distinct families. However, the position of Lineum (Molluginaceae) remains uncertain. Moreover, seed characters support the independence of Gisekia (Gisekiaceae) in a family of its own. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 189–206. 相似文献
10.
VINICIUS CASTRO SOUZA JULIANA DE PAULA-SOUZA 《Botanical journal of the Linnean Society. Linnean Society of London》2005,148(1):73-75
A new species, Achetaria latifolia V.C.Souza, is described and illustrated. It is characterized by its broadly ovate leaves, indument of stems and leaves of noncapitate hairs, and pubescent capsule. Achetaria latifolia is known only in the coastal dune-area of Cabo Frio region, Rio de Janeiro State, Brazil. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 73–75. 相似文献
11.
12.
ANGÉLICA CERVANTES HILDA FLORES OLVERA 《Botanical journal of the Linnean Society. Linnean Society of London》2005,149(2):241-256
Six new species of Bernardia from Mexico are described and illustrated. Species are distinguished by a combination of characters such as habit, leaf shape and size, indumentum, venation pattern, gland position, length of staminate inflorescence, number of bracts, number of flowers per bract, size of bracts and tepals, number of stamens, style type, fruit dehiscence, size, pubescence, trichome type, endocarp texture, seed shape, size and ornamentation, raphe length and micropyle position. Bernardia macrocarpa belongs to section Alevia ; B. chinantlensis to section Polyboea , which is recorded for the first time in Mexico; B. chiangii , B. mcvaughii , B. rzedowskii and B. valdesii belong to section Tyria , which is the most diverse section in Mexico. With the recognition of these six new species, Mexico becomes the area with the highest diversity for Bernardia . © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 241–256. 相似文献
13.
HAYR DUMAN MEHMET SAIROLU 《Botanical journal of the Linnean Society. Linnean Society of London》2005,147(3):357-361
Ferula coskunii H. Duman & M. Sağıroğlu sp. nov. from the Amanos Mountains (C6: Hatay-Turkey) is described and illustrated. It is closely related to F. drudeana Korovin, from which it differs mainly in habit, basal leaves, stem and mericarp features. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 357–361. 相似文献
14.
A new Swartzia (Leguminosae: Papilionoideae: Swartzieae) species with trimorphic stamens from Amazonian Brazil 总被引:1,自引:0,他引:1
VIDAL DE FREITAS MANSANO ANA LUCIA DE SOUZA 《Botanical journal of the Linnean Society. Linnean Society of London》2005,147(2):235-238
A new species Swartzia trimorphica Mansano & A. L. Souza (Leguminosae, Papilionoideae, Swartzieae) from the Amazonian Brazil, is described and illustrated. The new species is notable and distinct from all the other species of Swartzia by its highly unusual trimorphic stamens, while the other species have either an isomorphic or a dimorphic androecium. The new species is included in the section and subsection Swartzia , ser. Orthostylae based on its bracteolate pedicels, the cauligerous inflorescences, lateral style and the relative size of the ovary compared to the style. The atypically small gynoecium in the material suggests the possibility that flowers may be functionally unisexual. Field observations and more collections are needed to resolve this question. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 235–238. 相似文献
15.
A. L. ALLCOCK fls 《Zoological Journal of the Linnean Society》2005,143(1):75-108
Until recently, all papillated specimens of Pareledone were ascribed to the species Pareledone charcoti (Joubin, 1905), of which P. aurorae (Berry, 1917) was considered a junior synonym. Re-examination of the papillated type material of Pareledone, coupled with extensive fishing over several years off the Antarctic Peninsula, has led to a revision of this position. Seven new species of papillated Pareledone are identified from the Antarctic Peninsula region. They are identified by subtle taxonomic characters, such as the morphology and placement of their papillae, although traditional indices often fail to separate the species. Whilst apparently sympatric, there is some evidence of niche separation of these species with respect to depth. A key is provided for their identification. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 75−108. 相似文献
16.
17.
L. LLORENS L. GIL C. CARDONA M. FRANQUESA M. BOI 《Botanical journal of the Linnean Society. Linnean Society of London》2005,148(4):489-493
A new species, Oxalis ferae Llorens, Gil & Cardona (Oxalidaceae) from the Balearic islands (Spain) is described and illustrated. It is considered to be endemic to Mallorca. The morphological differences between the more closely related taxa of Oxalis section Corniculatae are discussed. IUCN threatened category and observations on the ecology of the populations are noted. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 489–493. 相似文献
18.
A new species of the thermophylic Tethyan relict prawn Typhlatya is described from two anchialine caves near Perpignan (southern France). The new species is closely related to a congener known only from a freshwater cave at Castellón (eastern Spain), about 400 km to the south-west, differing apparently only in the size and shape of the rostrum and the armature of the dactylus of the fifth pereiopod. Based on palaeogeographical evidence and assuming a sister-group relationship between both species, we suggest that their common ancestor could not be older than early Pliocene in age, and that it was already a stygobiont taxon adapted to live in shallow-water marine crevicular habitats. This ancestor would have vanished from the western Mediterranean after the cooling associated with the onset of northern Hemisphere glaciation, about 3 Mya, as documented for other Mediterranean marine taxa. Indeed, the genus is completely stygobiont and does not occur in fluvial environments. The Pyrenees represent a watershed boundary that eliminates the possibility of the derivation of one species from the other by active dispersal after establishment in continental waters. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 144 , 387–414. 相似文献
19.
AHMET DURAN ATLA OCAK 《Botanical journal of the Linnean Society. Linnean Society of London》2005,147(2):239-247
Hesperis turkmendaghensis A.Duran & A.Ocak sp. nov. (Cruciferae) is described and illustrated from Anatolia, Turkey. The species grows under mixed forest, open forest and shady slopes in Türkmen Dağı (B3 Eskişehir) in Central Anatolia. It is closely related to H. matronalis L. ssp. matronalis , an endemic confined to Central Anatolia. Diagnostic morphological characters are discussed. Notes are also presented on its ecology, biogeography and conservation status. In addition, the pollen characteristics and seed coat surface of H. turkmendaghensis and H. matronalis are examined by SEM. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 239–247. 相似文献
20.
FREDERIC LENS ERIK SMETS STEVEN JANSEN 《Botanical journal of the Linnean Society. Linnean Society of London》2004,144(2):161-179
The wood anatomical structure of 11 out of 13 genera from four tribes of the Vaccinioideae, namely Andromedeae s.s. , Gaultherieae, Lyonieae and Oxydendreae (Ericaceae s.l. ), is described using light and scanning electron microscopy. Several features of the secondary xylem support the tribal classification based on molecular data: arrangement of vessel-ray pitting, height of multiseriate rays and the shape of the body ray cells. Oxydendreae are clearly defined from the other representatives by various wood anatomical features. Gaultherieae can be distinguished from Lyonieae by differences in vessel perforation plates, vessel-ray pitting, height and structure of multiseriate rays, and occurrence of prismatic crystals, but the wood of Andromedeae s.s. is similar to Gaultherieae. Moreover, Andromedeae s.s. , Oxydendreae and Vaccinieae are characterized by their pith structure, whereas considerable variation in the pith cells is found in Lyonieae and Gaultherieae. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 161–179. 相似文献